“I'm a bit sad because I'm leaving a professionally-run club in Sassuolo and it was hard to say goodbye to everybody today, even if Barcelona are one of the biggest clubs in the world,” Boateng told Sky Sport Italia, in quotes carried by ESPN FC.

“It was a testing day, but saying goodbye to my teammates, [sporting director Giovanni] Carnevali and the coach meant so much to me.

“I've got a lot of respect for this side and that is why I had to say my goodbyes in person.”

Boateng only joined Sassuolo in the summer and has scored four goals in 13 Serie A outings, recently playing in a more advanced role.